摘要:
A power supply according to the principles of the inventions comprises two stages. The first stage is a power factor corrector stage. This stage provides the required line regulation, including greater than 95% power factor correction, and provides a range of outputs from approximately 5 volts to 200 volts with good load regulation at low voltages. The second stage is a soft switching power supply having good load regulation from approximately 40 to approximately 175 volts. An intermediate high voltage of the first stage supplies the input to the second stage, thereby achieving extremely good line regulation and low regulation.
摘要:
A converter utilizing a multifilar transformer having its primary and auxiliary windings made simultaneously, a technique known as bifilar winding, provides high efficiency and low noise. The multifilar winding technique yields minimum leakage inductance between the windings and reduces the proximity effect to a minimum achievable using most well-known wires. The converter utilizes an improved soft-switcher topology which advantageously reduces the interwinding capacitance between the primary and auxiliary windings of the transformer. The topology includes a resonant LC circuit interposed in series with one leg of the auxiliary winding and the auxiliary switch. The other leg of the auxiliary winding is at ground. A controller is provided to control switch timing such that the converter optimizes switch loss and resonant pulse loss.
摘要:
A dual mode converter is provided that may be operated as a variable-frequency, naturally-commutated controller in a Zero-Voltage-Switching mode and as a fixed-off-time controller in a Fixed-Off-Time mode. The converter includes four functional elements. A reference and biases element generates voltage references and biases utilized to determine various signal states. A Timing element generates a fixed off time signal and a voltage ramp signal utilized to create the dual modes of operation. A Catastrophic-Event element detects events that cause the converter output be inhibited and the controller to be restarted. A Mode Detection and Pulse Width Modulation element determines the mode of operation for the converter based on signal inputs from the other functional elements and modulates the output accordingly. In a primary mode, the controller utilizes variable frequency operation to deliver primary power. In a standby mode, the controller utilizes fixed frequency operation to provide low power (less than 5W).
摘要:
An exemplary power supply provides low power dissipation in standby mode by disabling the start-up circuit and by implementing variable frequency operation independent of the feedback signal. A standby mode detection circuit automatically implements the variable frequency operation, and an under voltage lockout signal implements the start-up circuit disable. Once the start time expires or when feedback control enables, the start-up circuit is disabled so that it dissipates negligible power. A voltage controlled oscillator responsive to the rectified DC line voltage provides for variable frequency operation in standby mode. The frequency output of the VCO is inversely proportional to the line voltage—as line voltage increases the switching frequency decreases, which decreases the output power.
摘要:
An inexpensive, robust plasma discharge emitter that repeatably creates a patterned charge on a substrate. To facilitate highly accurate charge deposition, each emitter contains a plasma well for confining the plasma within the emitter. Additionally, a plurality of emitters are arranged in an array to provide a practical charge patterning device. Furthermore, to fabricate an emitter or an array of emitters, a relatively low-cost, repeatable method of fabrication is used that relies upon conventional integrated circuit fabrication techniques.
摘要:
The invention is directed to a corona charging device having a powder feed with an outlet. The device has an internal charging cavity having an inlet and a charged powder outlet. The powder feed outlet is positioned at the internal charging cavity inlet. The device is adapted to guide a powder stream downstream from the powder feed outlet to the charged powder outlet. The device also includes a corona charger having one or more needle projections (each having a tip) positioned and adapted to facilitate a corona ion flow from the needle projections and intersecting the powder stream. The device also includes a rotating ground electrode adapted to be charged or grounded to attract the corona flow from the needle projections, and to rotate segments of the ground electrode between the internal charging cavity and a ground electrode cleaner.
摘要:
A device detects the location of objects in an environment by receiving an optical image and converting the optical image of the lost object into a color digital image. The device employs software to perform an analysis of the color digital image to detect the location of the one or more objects in the environment by using color and shape characteristics of the one or more objects. The software uses a range of the visible portion of the color space uniquely identified for the type of object in that environment and identifies those pixels in the color digital image that may be possible targets. Intensity of background and object size are used to exclude pixels as possible target objects.
摘要:
The present invention is directed to electrostatic chucks, methods for their use, the electrostatic deposition of objects, such as particles in a dry powder, onto recipient substrates, and the recipient substrates themselves that have been subjected to electrostatic deposition. In one aspect, the present invention provides an electrostatic chuck for electrostatically attracting an object or objects wherein the object is used in chemical or pharmaceutical assaying or manufacturing. The objects can be pharmaceutical substrates, for example, such as a pharmaceutical tablet. Additional embodiments of the invention provide chucks and their use to electrostatically attract particles, such as a pharmaceutically active ingredient, to a substrate, such as a tablet. In one aspect, the electrostatic chuck comprises a floating electrode, and is used to selectively attract particles to a substrate above the floating electrode, thereby providing for charge imaging for the deposition of particles in a selected image. Additionally, the invention provides comprising a sensing electrode, optionally for use with an electrostatic chuck, for sensing the number of particles attracted to the objects on the chuck or other substrate, thereby providing for deposition of an accurate amount of particles. Furthermore, the present invention provides objects having selected areas in which particles are applied to the object via electrostatic means.
摘要:
Provided is an electrostatic sensing chuck for attracting particles to a portion of a particle contact surface near a deposition electrode, the electrostatic sensing chuck comprising a pixel comprising: a deposition electrode (DE) for selectively establishing an attraction field (Ea) at the particle contact surface; a shield electrode (SE) oppositely biased with respect to the deposition electrode; a charge sensing circuit to measure charge accumulated on each of the deposition electrode and the shield electrode, wherein the charge sensing circuit subtracts a second charge it senses at the shield electrode from a first charge it senses at the deposition electrode, thereby determining accumulated charge at the deposition electrode balanced by accumulated charge at the shield electrode.
摘要:
Apparatus and a concomitant method for electrostatically depositing select doses of medicament powder at select locations on a substrate. Specifically, the apparatus contains a charged particle emitter for generating charged particles that charge a predefined region of a substrate and a charge accumulation control circuit for computing the amount of charge accumulated upon the substrate and deactivating the emitter when a selected quantity of charge has accumulated. Additionally, a triboelectric charging apparatus charges the medicament powder and forms a charged medicament cloud proximate the charged region of the substrate. The medicament particles within the medicament cloud electrostatically adhere to the charged region. The quantity of charge accumulated on the substrate at the predefined region and the charge-to-mass ratio of the medicament powder in the cloud control the amount (dose) of medicament deposited and retained by the substrate. Consequently, this apparatus accurately controls both medicament dosage and deposition location. Furthermore, since the substrate can be of any dielectric material that retains an electrostatic charge, the apparatus can be used to deposit medicament on substrates that are presently used in oral medicament consumption, e.g., substrates that are used to fabricate suppositories, inhalants, tablets, capsules and the like.